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New Scientist Live

Rubber algae help create first artificial reef in Mediterranean

TINY, artificial algae are being deployed in the first such effort to restore reefs in the Mediterranean.

They resemble coralline algae, which have a similar ecological role to corals: forming reefs using calcium carbonate structures that create diverse and complex environments.

But as the reefs they build are made from a soluble form of calcium carbonate, they are vulnerable to ocean acidification. So Federica Ragazzola at the University of Portsmouth, UK, partnered with researchers from the Italian National Agency for New Technologies, Energy and Sustainable Economic Development to test out artificial reefs. They wanted to see if these mimics could protect the organisms that live on natural coralline algae reefs and act as scaffolds on which real reefs would grow.

The team developed small plastic structures to mimic the coralline alga Ellisolandia elongata and how it moves. The 90 synthetic mini reefs, each with 20 fronds made of a highly elastic rubber material called silicone elastomer, are anchored in clear resin. “The material was chosen to match the properties of the algae and, more importantly, is non-toxic to the marine environment,” says Ragazzola.

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Last month, the mimics were fixed close to existing coralline algae reefs in the Gulf of La Spezia, in north-west Italy. Each is just 10 centimetres in diameter, so they can be easily nestled within natural reefs to encourage small organisms such as crustaceans, mussels and worms to move to the mimics. They will be monitored to see if this happens.

After one month, there are already signs that biofilms have formed on some of the artificial reefs, suggesting that microorganisms are beginning to colonise them. After a year, we should start to see some of the larger species establishing themselves on the mimics, says Ragazzola.

This article appeared in print under the headline “Rubber algae make artificial reefs off Italy”